1//===-- sanitizer_file.cpp -----------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===---------------------------------------------------------------------===//
8//
9// This file is shared between AddressSanitizer and ThreadSanitizer
10// run-time libraries.  It defines filesystem-related interfaces.  This
11// is separate from sanitizer_common.cpp so that it's simpler to disable
12// all the filesystem support code for a port that doesn't use it.
13//
14//===---------------------------------------------------------------------===//
15
16#include "sanitizer_platform.h"
17
18#if !SANITIZER_FUCHSIA
19
20#include "sanitizer_common.h"
21#include "sanitizer_file.h"
22#  include "sanitizer_interface_internal.h"
23
24namespace __sanitizer {
25
26void CatastrophicErrorWrite(const char *buffer, uptr length) {
27  WriteToFile(kStderrFd, buffer, length);
28}
29
30StaticSpinMutex report_file_mu;
31ReportFile report_file = {&report_file_mu, kStderrFd, "", "", 0};
32
33void RawWrite(const char *buffer) {
34  report_file.Write(buffer, internal_strlen(buffer));
35}
36
37void ReportFile::ReopenIfNecessary() {
38  mu->CheckLocked();
39  if (fd == kStdoutFd || fd == kStderrFd) return;
40
41  uptr pid = internal_getpid();
42  // If in tracer, use the parent's file.
43  if (pid == stoptheworld_tracer_pid)
44    pid = stoptheworld_tracer_ppid;
45  if (fd != kInvalidFd) {
46    // If the report file is already opened by the current process,
47    // do nothing. Otherwise the report file was opened by the parent
48    // process, close it now.
49    if (fd_pid == pid)
50      return;
51    else
52      CloseFile(fd);
53  }
54
55  const char *exe_name = GetProcessName();
56  if (common_flags()->log_exe_name && exe_name) {
57    internal_snprintf(full_path, kMaxPathLength, "%s.%s.%zu", path_prefix,
58                      exe_name, pid);
59  } else {
60    internal_snprintf(full_path, kMaxPathLength, "%s.%zu", path_prefix, pid);
61  }
62  if (common_flags()->log_suffix) {
63    internal_strlcat(full_path, common_flags()->log_suffix, kMaxPathLength);
64  }
65  error_t err;
66  fd = OpenFile(full_path, WrOnly, &err);
67  if (fd == kInvalidFd) {
68    const char *ErrorMsgPrefix = "ERROR: Can't open file: ";
69    WriteToFile(kStderrFd, ErrorMsgPrefix, internal_strlen(ErrorMsgPrefix));
70    WriteToFile(kStderrFd, full_path, internal_strlen(full_path));
71    char errmsg[100];
72    internal_snprintf(errmsg, sizeof(errmsg), " (reason: %d)", err);
73    WriteToFile(kStderrFd, errmsg, internal_strlen(errmsg));
74    Die();
75  }
76  fd_pid = pid;
77}
78
79static void RecursiveCreateParentDirs(char *path) {
80  if (path[0] == '\0')
81    return;
82  for (int i = 1; path[i] != '\0'; ++i) {
83    char save = path[i];
84    if (!IsPathSeparator(path[i]))
85      continue;
86    path[i] = '\0';
87    if (!DirExists(path) && !CreateDir(path)) {
88      const char *ErrorMsgPrefix = "ERROR: Can't create directory: ";
89      WriteToFile(kStderrFd, ErrorMsgPrefix, internal_strlen(ErrorMsgPrefix));
90      WriteToFile(kStderrFd, path, internal_strlen(path));
91      Die();
92    }
93    path[i] = save;
94  }
95}
96
97void ReportFile::SetReportPath(const char *path) {
98  if (path) {
99    uptr len = internal_strlen(path);
100    if (len > sizeof(path_prefix) - 100) {
101      Report("ERROR: Path is too long: %c%c%c%c%c%c%c%c...\n", path[0], path[1],
102             path[2], path[3], path[4], path[5], path[6], path[7]);
103      Die();
104    }
105  }
106
107  SpinMutexLock l(mu);
108  if (fd != kStdoutFd && fd != kStderrFd && fd != kInvalidFd)
109    CloseFile(fd);
110  fd = kInvalidFd;
111  if (!path || internal_strcmp(path, "stderr") == 0) {
112    fd = kStderrFd;
113  } else if (internal_strcmp(path, "stdout") == 0) {
114    fd = kStdoutFd;
115  } else {
116    internal_snprintf(path_prefix, kMaxPathLength, "%s", path);
117    RecursiveCreateParentDirs(path_prefix);
118  }
119}
120
121const char *ReportFile::GetReportPath() {
122  SpinMutexLock l(mu);
123  ReopenIfNecessary();
124  return full_path;
125}
126
127bool ReadFileToBuffer(const char *file_name, char **buff, uptr *buff_size,
128                      uptr *read_len, uptr max_len, error_t *errno_p) {
129  *buff = nullptr;
130  *buff_size = 0;
131  *read_len = 0;
132  if (!max_len)
133    return true;
134  uptr PageSize = GetPageSizeCached();
135  uptr kMinFileLen = Min(PageSize, max_len);
136
137  // The files we usually open are not seekable, so try different buffer sizes.
138  for (uptr size = kMinFileLen;; size = Min(size * 2, max_len)) {
139    UnmapOrDie(*buff, *buff_size);
140    *buff = (char*)MmapOrDie(size, __func__);
141    *buff_size = size;
142    fd_t fd = OpenFile(file_name, RdOnly, errno_p);
143    if (fd == kInvalidFd) {
144      UnmapOrDie(*buff, *buff_size);
145      return false;
146    }
147    *read_len = 0;
148    // Read up to one page at a time.
149    bool reached_eof = false;
150    while (*read_len < size) {
151      uptr just_read;
152      if (!ReadFromFile(fd, *buff + *read_len, size - *read_len, &just_read,
153                        errno_p)) {
154        UnmapOrDie(*buff, *buff_size);
155        CloseFile(fd);
156        return false;
157      }
158      *read_len += just_read;
159      if (just_read == 0 || *read_len == max_len) {
160        reached_eof = true;
161        break;
162      }
163    }
164    CloseFile(fd);
165    if (reached_eof)  // We've read the whole file.
166      break;
167  }
168  return true;
169}
170
171bool ReadFileToVector(const char *file_name,
172                      InternalMmapVectorNoCtor<char> *buff, uptr max_len,
173                      error_t *errno_p) {
174  buff->clear();
175  if (!max_len)
176    return true;
177  uptr PageSize = GetPageSizeCached();
178  fd_t fd = OpenFile(file_name, RdOnly, errno_p);
179  if (fd == kInvalidFd)
180    return false;
181  uptr read_len = 0;
182  while (read_len < max_len) {
183    if (read_len >= buff->size())
184      buff->resize(Min(Max(PageSize, read_len * 2), max_len));
185    CHECK_LT(read_len, buff->size());
186    CHECK_LE(buff->size(), max_len);
187    uptr just_read;
188    if (!ReadFromFile(fd, buff->data() + read_len, buff->size() - read_len,
189                      &just_read, errno_p)) {
190      CloseFile(fd);
191      return false;
192    }
193    read_len += just_read;
194    if (!just_read)
195      break;
196  }
197  CloseFile(fd);
198  buff->resize(read_len);
199  return true;
200}
201
202static const char kPathSeparator = SANITIZER_WINDOWS ? ';' : ':';
203
204char *FindPathToBinary(const char *name) {
205  if (FileExists(name)) {
206    return internal_strdup(name);
207  }
208
209  const char *path = GetEnv("PATH");
210  if (!path)
211    return nullptr;
212  uptr name_len = internal_strlen(name);
213  InternalMmapVector<char> buffer(kMaxPathLength);
214  const char *beg = path;
215  while (true) {
216    const char *end = internal_strchrnul(beg, kPathSeparator);
217    uptr prefix_len = end - beg;
218    if (prefix_len + name_len + 2 <= kMaxPathLength) {
219      internal_memcpy(buffer.data(), beg, prefix_len);
220      buffer[prefix_len] = '/';
221      internal_memcpy(&buffer[prefix_len + 1], name, name_len);
222      buffer[prefix_len + 1 + name_len] = '\0';
223      if (FileExists(buffer.data()))
224        return internal_strdup(buffer.data());
225    }
226    if (*end == '\0') break;
227    beg = end + 1;
228  }
229  return nullptr;
230}
231
232} // namespace __sanitizer
233
234using namespace __sanitizer;
235
236extern "C" {
237void __sanitizer_set_report_path(const char *path) {
238  report_file.SetReportPath(path);
239}
240
241void __sanitizer_set_report_fd(void *fd) {
242  report_file.fd = (fd_t)reinterpret_cast<uptr>(fd);
243  report_file.fd_pid = internal_getpid();
244}
245
246const char *__sanitizer_get_report_path() {
247  return report_file.GetReportPath();
248}
249} // extern "C"
250
251#endif  // !SANITIZER_FUCHSIA
252